738 



JOURNAL OF THE EOYAL HORTICULTURAL SOCIETY. 



described by Count Schwerin, the well-known German specialist of the 

 genus Acer. The leaves are mostly three-lobed, with lacerated margins, and 

 in colour somewhat resemble the older variety known as digitatum aureo- 

 marginatUm ; but the most noteworthy peculiarity of the leaves is seen in 

 outgrowths from the margin, of various forms, all more or less sharply 

 pointed and of a brownish-green colour, offering a curious contrast to the 

 colouring of the blade. The variety is named Wittmackii, in compliment 

 to the eminent editor of the " Gartenflora." — A. H. K. 



Aeoridium, The Genus. By R. A. Rolfe (Orch. Bev. vol. xii. p. 

 219). — Interesting particulars and the enumeration of the known species 

 are appended. — H. J. C. 



Africa, Tropical Plants of the Northern Temperate Zone in 

 their Transition to the High Mountains of. By A. Engler (Ann. 

 Bot. xviii. Oct. 1904, pp. 523-540). — In Africa a considerable number of 

 highland forms have been recorded whose nearest relatives are to be 

 looked for in the northern temperate zone or other widely separated 

 countries. • 



The identity or otherwise of these with the forms living in other 

 latitudes and the origin of the African species are the main points dis- 

 cussed in the paper. 



A number of instances are given of species, of various orders, becoming 

 modified by advancing from the temperate zone to high altitudes in Africa. 

 The author gives his views as to climatical adaptations. — A. D. C. 



Agronomy, Instruction in, at some Agricultural Colleges. 



By A. C. True and D. J. Crosby (U.S.A. Dep. Agr. Office Exp. Stn.,Bull. 

 127 ; 1903). — The question of agronomy or plant production as taught and 

 practised at several of the agricultural colleges in the United States is 

 set forth. General views of the colleges in question, with detailed plates 

 of the laboratories and class-rooms showing apparatus used for the various 

 experiments. A good outline of the manner in which students in the 

 States are trained to carry out their duties in regard to profitable plant 

 production is given. In addition to the above, detailed courses are given, 

 which should interest all those connected with horticultural teaching in 

 this country. — K. F. E, 



Alder, The. By W. J. Bean (Garden, No. 1694, p. 319 ; 7/5/1901). 

 The Alder is one of the most suitable of all trees, native or foreign, for 

 planting in wet situations. On steep banks of streams and ponds it is 

 particularly useful because its roots hold the soil well together. In habit the 

 Alder varies. At Whitton Park, near Hounslow, growing on the margins 

 of the lake are some tall specimens 90 feet or so high. The number of 

 trees that can be grown in very moist situations is not so great but that 

 the Alder may be welcomed among them. To the more graceful outlines 

 of Willow or Poplar the stiffer carriage of the Alder affords a contrast 

 that not only pleases in itself, but is valuable in that it accentuates the 

 beauties of its associates. There are several varieties : the best known is 

 lac'uiiata, a tree wild in the north of France, and more ornamental than 

 the type because of the deeply cut leaves. Of a similar type, but even 



